RU141899U1 - DEVICE FOR APPLYING FILM COATINGS ON GRANULATED, CAPSULATED AND TABLET FORMS - Google Patents

Abstract

Apparatus for applying film coatings on granular, capsule and tablet forms containing a working chamber, a spray device, a gas distribution grill, characterized in that the inner surface of the working chamber of the apparatus in contact with fluidized forms is made in the form of an ordered set of uniformly sized hemispheres, the large circles of which lie on the surface of the cylinder, and the distance between the centers of adjacent hemispheres is from 0.866-1 of the diameter of the hemisphere.

Description

The utility model relates to the chemical and food industries, in particular to devices for applying film coatings to granular, encapsulated and tabulated forms in a fluidized state.

A device for coating granules is known (see AS USSR No. 1088777, 1984), comprising a housing with vibrating inclined shelves and nozzles located under each shelf for spraying surface-active substances therein. In the case of free fall of granules in a continuous stream onto sequentially located vibrating inclined shelves, granules of material are thrown up fan-shaped and wander in the pollination zone. Here they are intensively mixed and at the same time a surfactant is applied with the help of nozzles. However, in this installation, the formation of a film is possible by touching particles of wave-like walls or vibrating shelves.

The closest technical solution is the apparatus for coating dispersed materials in a fluidized bed (see A.S., No. 1457986, 1989), which contains a working chamber, a spray device placed in it, a gas distribution grid, under which there are blades made of elastic material that allows you to smoothly change the curvature of their profile, and a fan connected by a pipe.

When the apparatus is operating, a certain layer of the material to be processed is loaded and the fan is turned on, and the necessary curvature is imparted to the blades, providing a smooth change in the direction of the air flow from the center to the periphery of the apparatus to form a fluidized bed of particles with a variable density of their distribution in the layer. Then the sawing device is turned on and the film former solution is supplied to the particles.

After coating, the flow of solution and air is turned off and coated particles are discharged. However, this apparatus is relatively difficult to manufacture and not suitable for the application of enteric film coatings due to the presence of a large number of contact surfaces of the working surfaces of the apparatus with fluidized forms.

The technical task is to create a device that allows for uniform coating of film coatings on granular, encapsulated and tabletted forms in a fluidized state.

The technical result is an improvement in the design of the working chamber of the device.

It is achieved by the fact that in a device containing a working chamber, a spray device and a gas distribution grill, the inner surface of the working chamber of the apparatus in contact with fluidized forms is made in the form of an ordered set of uniformly sized hemispheres, large circles of which lie on the surface of the cylinder, and the distance between the centers of adjacent hemispheres ranges from 0.866-1 of the hemisphere diameter.

In FIG. 1 shows a General view of the proposed apparatus with a section of the working chamber; in FIG. 2 - the inner surface of the working chamber of the apparatus. The apparatus has a vertical working chamber 1 in the form of a hollow cylinder, a gas duct 2 for supplying a fluidizing agent, made in the form of a hollow truncated cone, the larger base of which is coaxially aligned with the lower base of the working chamber 1, the gas distribution grid 3 is made in the form of a disk, coaxially mounted between the working chamber 1 and a gas duct 2 for supplying a fluidizing agent, a gas duct for removing the fluidizing agent 4, made in the form of a hollow truncated cone, the larger base of which is coaxially aligned with the upper axis Hovhan processing chamber 1, and the small base is connected via line 5 to a cyclone 6, the dispersing device 7 for dispersing the coating film fed through conduit 8, screw feeder 9 with a hopper 10 for loading the native granular encapsulated, tableted forms.

The device operates as follows. From the hopper 10 by means of a screw batcher 9, the required number of native forms is fed into the working chamber 1 of the apparatus. Then, through the gas duct 2, a fluidizing agent, for example, air, is supplied to the working chamber 1 and the process of fluidization of native forms takes place. The coating is carried out by a spray device 7 by dispersing the shell into a pseudo-boiling layer of molds. After the dispersion process is completed, the velocity of the fluidizing agent in the gas duct 2 is increased to provide pneumatic conveying of the coated forms through the pipeline 5 to cyclone 6, where due to the emerging centrifugal force, the finished product is separated from the spent fluidizing agent aimed at regeneration.

Without modernization of the working chamber, a random collision of forms with the walls of the working chamber inevitably occurs in the fluidization process. The applied coating has relatively high adhesion and cohesion characteristics, therefore, until the final moisture content of the coating, fluidized forms tend to adhere to the working chamber and agglomerate. Thus, despite the conditions of the active action of the fluidizing agent during the application process, the probability of adhesion and fixation of forms on the walls of the working chamber is high, which in turn leads to an increase in the share of substandard finished products.

The proposed shape of the inner surface of the working chamber of the apparatus allows the product to come into contact with the working surface only at several points, which during fluidization eliminates sticking or long-term fixation of forms on the walls of the working chamber. An increase in the distance between the centers of the bases of adjacent spheres of more than 1 hemisphere diameter leads to the formation of stagnant zones between spheres where accumulation of the applied coating is possible. The drying of the shell in the voids makes the process of cleaning the working chamber difficult, and the subsequent ingress of dry shell particles into the working area of the apparatus is an additional factor for reducing the quality of the applied coating. A decrease in the distance between the centers of the bases of adjacent spheres of less than 1 hemisphere diameter causes an increase in the number of contact points per unit of the working surface, which, given the presence of a shell between the contacting surfaces, increases the likelihood of adhesion and fixation of fluidized forms.

The number of contact points directly depends on the form of the drug, as a result of which it is recommended to maintain the ratio l <x <2l,

where x, mm - the largest size of the fluidized form,

l, mm - the distance between the centers of the bases of adjacent spheres.

A positive effect - the device allows for uniform application of film coatings on granular, encapsulated and tablet forms in a fluidized state, which will improve the quality of the finished product.

Claims (1)

Apparatus for applying film coatings on granular, capsule and tablet forms containing a working chamber, a spray device, a gas distribution grill, characterized in that the inner surface of the working chamber of the apparatus in contact with fluidized forms is made in the form of an ordered set of uniformly sized hemispheres, the large circles of which lie on the surface of the cylinder, and the distance between the centers of adjacent hemispheres is from 0.866-1 the diameter of the hemisphere.

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